Antineoplaston Therapy in Treating Patients With Meningioma

DISEASE CHARACTERISTICS: Histologically confirmed meningioma that has progressed or recurred following surgical resection and radiotherapy Evidence of residual tumor by MRI scan performed within two weeks prior to study entry PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Karnofsky 60-100% Life expectancy: At least 2 months Hematopoietic: Hemoglobin at least 9 g/dL WBC at least 2000/mm3 Platelet count at least 50,000/mm3 Hepatic: Bilirubin no greater than 2.5 mg/dL SGOT/SGPT no greater than 5 times upper limit of normal No hepatic failure Renal: Creatinine no greater than 2.5 mg/dL No history of renal conditions that contraindicate high dosages of sodium Cardiovascular: No chronic heart failure No uncontrolled hypertension No history of congestive heart failure No history of other cardiovascular conditions that contraindicate high dosages of sodium Pulmonary: No serious lung disease, such as chronic obstructive pulmonary disease Other: Not pregnant or nursing Fertile patients must use effective contraception during and for 4 weeks after study No active infection No other serious concurrent disease PRIOR CONCURRENT THERAPY: Biologic therapy: At least 4 weeks since prior immunotherapy and recovered No concurrent immunomodulatory agents Chemotherapy: At least 4 weeks since prior chemotherapy (6 weeks for nitrosoureas) and recovered No concurrent antineoplastic agents Endocrine therapy: Concurrent corticosteroids allowed At least 4 weeks since prior therapy with mifepristone and recovered Radiotherapy: At least 8 weeks since prior radiotherapy and recovered Surgery: Recovered from prior surgery Other: Prior cytodifferentiating agent allowed No prior antineoplaston therapy